老年SD大鼠脑组织间液内MR示踪剂扩散特征的研究

发布时间：2019-03-02 14:30

【摘要】：目的随着脑组织衰老的进展,神经细胞代谢及分泌产物在脑细胞外间隙(ECS)转运及引流特性发生不可逆性改变,本研究通过MR示踪剂在ECS内扩散的特征反映老年SD大鼠脑组织间液流动的改变,并通过软件计算将其量化。材料与方法分别选择实验组老年SD大鼠(15~17个月)8只及对照组正常成年SD大鼠(7~10个月)15只,尾状核注射MR示踪剂钆喷酸葡胺,分别于0.25 h、0.5 h、1 h、2 h、3 h、4 h进行MRI扫描,观察造影剂在尾状核的动态分布,并测量造影剂的扩散及清除速率。结果实验组SD大鼠的示踪剂在ECS内的扩散率D*为(3.25±0.46)×10-4 mm2/s,与对照组的(3.32±0.70)×10-4 mm2/s比较,差异无统计学意义(t=1.739,P0.05);但实验组尾状核区的示踪剂清除速率k'为(0.29±0.08)×10-4/s,较对照组的(0.62±0.12)×10-4/s明显减低,差异有统计学意义(t=11.602,P0.05)。结论SD大鼠脑衰老组织的退行性改变引起ECS结构等变化,使脑组织间液清除减慢,这可能与代谢产物蓄积并最终诱发多种老年性疾病有密切的关系。
[Abstract]:Objective with the development of brain senescence, the characteristics of (ECS) transport and drainage of neuronal metabolism and secretion products in the extracellular space of brain cells were irreversely changed. In this study, the characteristics of diffusion of MR tracer in ECS were used to reflect the changes of fluid flow in brain tissue of aged SD rats, and the changes were quantified by software calculation. Materials and methods eight aged SD rats (15 ~ 17 months) in the experimental group and 15 normal adult SD rats (7 ~ 10 months) in the control group were selected. The caudate nucleus was injected with MR tracer gadolinium gluconate at 0.25 h, 0.5 h, 1 h, 2 h, respectively, and the control group was treated with MR tracer Gadolinium gluconate at 0.25 h, 0.5 h, 1 h, 2 h, respectively. The dynamic distribution of the contrast agent in the caudate nucleus was observed by MRI scanning at 3 h and 4 h, and the diffusion and clearance rate of the contrast agent were measured. Results the diffusivity of tracer in ECS of SD rats in experimental group was (3.25 卤0.46) 脳 10 脳 4 mm2/s, and (3.32 卤0.70) 脳 10 渭 4 mm2/s in control group, there was no significant difference (t = 1.739, P0.05). However, the tracer clearance rate of the caudate nucleus in the experimental group was (0.29 卤0.08) 脳 10 ~ (4) 渭 s, which was significantly lower than that in the control group (0.62 卤0.12) 脳 10 ~ 4 / s) (t = 11.602, P0.05). Conclusion the degenerative changes of brain senescence tissue in SD rats cause changes in ECS structure and decrease the clearance of fluid between brain tissues, which may be closely related to the accumulation of metabolite and eventually induce a variety of senile diseases.
【作者单位】：兰州大学第一医院放射科;北京大学第三医院放射科;
【基金】：国家自然科学基金项目(81171080)
【分类号】：R445.2;R741

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